This plugin hasnt been tested with the latest 3 major releases of WordPress. It may no longer be maintained or supported and may have compatibility issues when used with more recent versions of WordPress.

Spectacu.la Advanced Search

Description

This plug-in provides you with more relevant search results than are currently
available to the normal WordPress search and it should also do so with less of a
performance hit on the db than the normal WordPress search. We use the MySQL
commands MATCH () AGAINST () as opposed to WordPress’ use of LIKE to do our
queries which are not as heavy on the db. The only issue we have with “match
against” is that we need an index on the columns we intend to search on.

Installation

The install

Upload spec-adv-search folder to /wp-content/plugins/spec-adv-search/
or the content of the folder to /wp-content/mu-plugins/.
If the directory doesn’t exist then create it.

Activate the plugin through the ‘Plugins’ menu in WordPress.

You should now see an extra menu Advanced search show up under the
settings menu in the main admin sidebar.

Go to the new page and hit the “Create Index” button. Once the index has
been created you’ll then be able to tick the enable box at the top of the
page.

The config

For these search methods to work you’ll need a FULLTEXT index on your
post_content and post_title in the wp_posts table. This can be done by using
the “create index” button. There are some things to be aware of before you
proceed.

Firstly adding the index will likely double the size of your wp_posts
table, this in and of itself isn’t a problem however if you’re running up
against the upper limits of your hosts allowed size then creating an index
may push you over that limit. If you do hit your size limit nothing bad
should happen but it would be best if you backed up your database first just
in case. Always a good idea to run a backup before anything is done to
change the db.

Second thing you should know is that the index creation is handled by a
Wordpress cron job. Some hosts have problems with wp_cron and if your host
is one of those then you will see this “The index creation/deletion is
scheduled to start after {date and time}” below the button for a long time
after the job was supposed to run. Don’t worry if it’s only a few mins as
that is quite normal. If you do have a problem with wp_cron on your server
you may find future dated posts don’t become live when you hoped. We can, if
you have something like PHPMyAdmin, create the indexes manually by running
these commands against your WordPress db:

Thirdly creating the indexes could take quite some time depending upon
your server set up. Once the index creation kicks in, unless your server
creates the index so quickly that it completes the creation before the
command to collect the status has run, you should see “Creating index on
post_—–. MySQL is returning the following message:” Don’t panic if you
see something like “repair by sorting” or “copy to tmp table” as these are
expected messages but if you get “Repair with keycache” still don’t panic
just be prepared to wait a long while for the index to complete its
creation.

Once the index is live you should be able to tick the enable button. Now we
get to choose from up to 5 different modes of search:

Default mode: This will find posts containing any of the term, the more
of the terms there are in a post the higher relevance score it receives
and thus the higher in the results it will appear (presuming sorting by
rank). If two or more terms are searched for but only one can be found
then posts matching that one will be returned. Terms matched in titles
count as one and a half as much as those in the content.

Boolean mode: Very much the same as default mode but you get several
extra operators that can alter a query. Adding + or – to the head of a
term will either make it so that you return posts that must have the
term or must not have the term. > or < will increase or decrease the
importance of a word. So for example (phone >droid) would find all phone
post and droid post but droid posts would be considered more important.
A full explanation of the operators can be found here.

With query expansion: This kind of search can find posts related to your
search terms but don’t necessarily contain any of the terms entered. So
search for “android” for example and it will use posts that contain the
word android to find words that are related to it. So it may deem that
you want posts about robots too or it may also figure you want post
relating to Google’s phone OS it really depends upon your sites content.
For this mode you’ll need to tweak the relevance limit bases on what has
been returned for your content otherwise it can end up returning all
posts on your site. Not too big a problem if ordered by relevance but
if ordered by date your results will make no sense at all.

In natural language mode: If you have MySQL 5.1 or better you will have
two more modes available to you. First is In natural language mode which
is mostly the same as default mode and in natural language more with
query expansion which is functionally the same as the with query
expansion.

If your server works with wp_cron then you can set up a periodic table
optimise that will help keep your table index in order. If your site changes
rarely then you can set it to run infrequently or not at all and just use
the “optimise table” button to do it as and when you want/need to. The more
accurate your index is the better your search results will be and the lower
the load on the db. All good basically. The optimise will kick in after the
time it is set to run but wp-cron requires a visitor to kick off the job. So
if you set it to start at 3:00am and you don’t get an activity on your site
until 10am the next day the job won’t start until 10am. This shouldn’t be a
problem as most optimisations apply very little load and take only a few
second to run.

FAQ

With query expansion mode returns some odd results?

This mode guesses what the searcher was after from words MySQL thinks are
related to the terms searched for. If your content implies an association
between two otherwise unrelated terms then MySQL will make an assumption
that they are related. For example if you mention Ducks and Strawberries
together in a few post your index will see a relationship and searches for
Ducks may return results for Strawberries.

Contributors & Developers

“Spectacu.la Advanced Search” is open source software. The following people have contributed to this plugin.